Costlowk

Alright, here's my back story. My mustang has had problems with the MAF before, but I just cleaned it and it's been good for like a year now. However I've recently just traveled cross country and it started to show signs that it was having the same problems again. I've been busy though and never got around to taking care of it. I'm not sure if this could have caused any problems but about a week ago I managed to run myself out of gas (stupid I know) so I went and filled up my gas can and got some gas in my car without any problems. However, the next time I filled up my car it had a hard time starting and kept stalling after I took it out of park. Finally it seemed to be running normal and I decided to continue on my 9 hour trip cause my wife was in town and nothing was going to ruin our vacation! So a couple hours down the freeway my engine kinda just starts hiccuping almost as if someone tap on the brakes really fast and then after that the RPMs starting revving really high but I wasn't accelerating almost as if the car had been thrown in neutral. My car is an automatic and I had the cruise control set so I know it wasn't me so I quickly pulled into a Firestone and they kept saying that it sounded like transmission problems but finally one guy mentioned the Mass Airflow Sensor and it finally clicked in my head that I've had problems with that before. So I cleaned it and made it to and from my vacation with my wife just fine. However, the next weekend I filled up again, and my car almost stalled only once so I thought it was ok, but after driving for awhile on the freeway again it started to have the same problems so I pulled over and cleaned it again and it ran fine the rest of the trip except on the way back. When I filled up once again it would stall every time I took it out of park and I had to keep the engine revved just to go. Then a little later it had the same hiccuping problems, so I cleaned it again and made it home. Finally the latest incident was at like 3 in the morning when I dropped my wife off at the airport. It's only an hour and a half trip and I made it there just fine, but then I filled up on gas and on the way back it had major problems. Normally every time the engine revved really high while I was on the freeway if I just let off the gas it return to normal and I'd be able to drive just fine afterwards, but this time it wouldn't go back to normal and wouldn't accelerate or anything and the Check Engine Light popped up. So I pulled off the the side of the road and cleaned my MAF by flashlight and it ran fine for like half an hour until it did it again. I HAD to get to work that morning so I did the same thing, and it ran for about another half hour till it did the same thing again. So I cleaned it again and finally made it home and now that car is just going to sit in the parking lot until someone can give me a good answer on what is wrong and how much it'll probably end up costing me. I'm already broke from flying my wife down to visit and going on 2 separate vacations. I just might have to sell my mustang if it's something serious, and I really don't want to, I love that car. So can someone please help me? So sorry for the long story, I just wanted to include every detail haha.

AdderMk2

well... stop dicking with your MAF before you break it.

Read your Check Engine codes, and for the love of God... replace your fuel filter. A full tune up should be in order. Also, does the car still have stock cats?

Next time the car just completely dies on you, DONT TOUCH THE MAF! Chck your fuel pressure and check for spark.

ttocs

yea I would gues that the repeated removal and cleaning might have created a small short in it. taking it out and cleaning it might cool it off and help to fix the short for a small time but hit a good bump and it might go out. Start it up and then go give the maf and its wiring a good going over. STart off with some technical taps with the tips of your fingers on the maf while it is running. If nothing happens then close your hands and use your knuckles to give it a little harder thump. Don't be afraid to give it a good knock as it should be able to take it with the bumps a car is shown in a daily drive. If that still doesn't do anything pay attention to the wiring and pull/tug on it gently into different positions(again while its running) and see if you can get it to hickup again.

I would guess that it gets hot, something expands and then you have your short. Cleaning it could cool it off enough to fix the short for a short time but as you saw it would come back.

If the engine studders during any of this replace the maf.

mjr46

no one can do that....just a guess is all that'll be given..cost = 0 to infinite amount.....follow adder's advice for now

Costlowk

Ya I'm not exactly a mechanic and wasn't sure what else to do out in the middle of nowhere. Thanks for the advice I'll take care of that stuff asap. I'm pretty sure the cats are stock. The previous owner did a few mods but I don't think that was one of them. I'm pretty sure all he installed was a cold air intake, and a positraction.

88GTBLACK

our cars come with posi rears. give it a full throttle run stop and check the exhaust. if there are chambers in the exhaust pipes glowing forward of the front seats under the car, you need to go on summit and get a mid pipe. Report back after a full tune up if it doesnt go away.

88GTBLACK

our cars come with posi rears. Report back after doing a full tune up including the fuel filter and wiggle test the MAF. and give it a full throttle run stop after installing the stuff and check the exhaust right after. if there are chambers in the exhaust pipes glowing forward of the front seats under the car, you need to go on summit and get a mid pipe. good luck

MustangBradley

The common denominator of your post seems to be filling your car up. I'd check your tank vent (if the Fox has a vent, I don't remember) for blockage. If it is blocked, and you have a full tank, you only have a little bit of air space. As you drive, you are removing fuel from the tank. If the vent is blocked, you are creating a vacuum in the tank which the fuel pump has to battle against in order to remove more fuel. At some point, the vacuum becomes so great that the pump can't remove anymore fuel, so you get the hiccups and starvation issue.

wydopnthrtl

This is a line of thinking that might make "common sense" but actually the opposite takes place and here is why:
when a returned EFI system is working, pressure builds in the tank from the fuel being heated due to friction of being pumped, passing through a hot engine fuel rail, and also by the fuel airating as it spues back into the tank.

Also, fuel tank pressure deltas (positive or negative) would not cause the tranny to allow free revving while in gear. Interestingly, I've seen bad MAF sensors do this very thing!


To the OP, if there is a next time.. just unplug the MAF and drive home or to a shop. This will force the ECU to reference several "limp home" charts within the tune. The tranny will shift differently with it unplugged and it'll throw a CEL.. but it won't slip **if** its only the MAF that is bad.

Also, running a EFI out of fuel opens up the possibility of pumping debris through the pump and into the fuel filter.

IMO, At the very least change the filter and I'd not be supprised if the MAF sensor is bad. If/when you replace the sensor.. make sure to disconnect the battery and turn on the lights (to clear the KAM). Turn off the lights and reconnect. Put it through the quick idle learn procedure and you'll most likely be good to go.

Regards,
Rich

wydopnthrtl

Yeah you can tell from his descriptions that he is equipped to do this... on the side of the road... in the dark.

Adder.. try Love instead of a hammer. Makes life so much easier.